Engines operating with one or more cylinders as dedicated EGR cylinders enjoy greatly simplified controls and pressure management, fewer hardware devices, and other benefits. However, these simplifications come at the cost of a loss of control over the system, including a loss of control of the EGR fraction. When nominal cylinders are dedicated to providing EGR, and standard fueling and controls are applied, the EGR fraction provided by the cylinders is limited to the simple ratio of the number of EGR cylinders to the total number of cylinders. For example, an engine with one cylinder dedicated to EGR and four cylinders total will operate at a 25% EGR fraction if all of the cylinders are operated in the same manner. Additionally, an engine having dedicated EGR cylinders provides an opportunity for greater control over the temperature and composition of gases at the intake manifold, if a system could be developed to take advantage of this opportunity. Therefore, further technological developments are desirable in this area.